tag can be deduced from iso-tag.

Author: JulienPalard

build_docs.py

@@ -206,13 +206,16 @@ def __gt__(self, other):
 
 @dataclass(frozen=True, order=True)
 class Language:
-    tag: str
     iso639_tag: str
     name: str
     in_prod: bool
     sphinxopts: tuple
     html_only: bool = False
 
+    @property
+    def tag(self):
+        return self.iso639_tag.replace("_", "-").lower()
+
     @staticmethod
     def filter(languages, language_tags=None):
         """Filter a sequence of languages according to --languages."""
@@ -1024,11 +1027,10 @@ def parse_languages_from_config():
     config = tomlkit.parse((HERE / "config.toml").read_text(encoding="UTF-8"))
     languages = []
     defaults = config["defaults"]
-    for name, section in config["languages"].items():
+    for iso639_tag, section in config["languages"].items():
         languages.append(
             Language(
-                name,
-                section.get("iso639_tag", name),
+                iso639_tag,
                 section["name"],
                 section.get("in_prod", defaults["in_prod"]),
                 sphinxopts=section.get("sphinxopts", defaults["sphinxopts"]),

config.toml

@@ -1,6 +1,5 @@
 [defaults]
 # name has no default, it is mandatory.
-# iso639_tag defaults to section key.
 in_prod = true
 html_only = false
 sphinxopts = [
@@ -72,8 +71,7 @@ sphinxopts = [
 name = "Polish"
 in_prod = false
 
-[languages.pt-br]
-iso639_tag = "pt_BR"
+[languages.pt_BR]
 name = "Brazilian Portuguese"
 
 [languages.tr]
@@ -84,17 +82,15 @@ name = "Ukrainian"
 in_prod = false
 html_only = true
 
-[languages.zh-cn]
-iso639_tag = "zh_CN"
+[languages.zh_CN]
 name = "Simplified Chinese"
 sphinxopts = [
     '-D latex_engine=xelatex',
     '-D latex_elements.inputenc=',
     '-D latex_elements.fontenc=\\usepackage{xeCJK}',
 ]
 
-[languages.zh-tw]
-iso639_tag = "zh_TW"
+[languages.zh_TW]
 name = "Traditional Chinese"
 sphinxopts = [
     '-D latex_engine=xelatex',